INTRODUCION

Appropriate soft tissue balance is an important factor for postoperative function and long survival of total knee arthroplasty(TKA). Soft tissue balance is affected by ligament release, osteophyte removal, order of soft tissue release, cutting angle of tibial surface and rotational alignment of femoral components. The purpose of this study is to know the characteristics of soft tissue balance in ACL deficient osteoarthritis(OA) knee and warning points during procedures for TKA.

Background

To conduct a systematic review and network meta-analysis of RCTs with the aims of comparing relevant clinical outcomes (i.e. VAS, WOMAC total and sub-score score, Lequesne Algofunctional index, joint space width change and adverse events) between diacerein, glucosamine and placebo.

Introduction. Patients undergoing total knee arthroplasty (TKA) with end-stage osteoarthritis of knee have secondary foot and ankle pathology. Some compensatory changes occur at ankle and subtalar joint secondary to malalignment and deformity at the knee joint. Purpose was to evaluate the changes in hindfoot malalignment and foot deformities in patients with advanced osteoarthritis of knee requiring TKA and effect of correction of knee deformities post TKA on foot/Ankle alignment. Methods. 61 consecutive patients with Kellgren-Lawrence grade IV osteoarthritis knee undergoing TKA were enrolled in a prospective blinded study. Demographic data, deformities at knee and ankle, hindfoot malalignment and functional outcome scores such as VAS, KSS, WOMAC scores, Foot and Ankle Disability Index (FADI) and Foot posture index (FPI) were recorded preoperatively and postoperatively at 6, 12 weeks and final follow up (range: 6–21 months; mean: 14.2months). Results. Statistically significant improvement was observed in KSS score, WOMAC score, FADI and FPI after TKA. There was improvement in ankle valgus after correction of knee varus deformity. Hind foot changes mainly occured at subtalar joint. Hallux valgus (10 patients), and Pesplanus (5 patients) were associated with advanced osteoarthritis of knee. Gait profile score and Gait deviation index improved significantly after TKA. There was increased stance phase and decreased stride length in knee osteoarthritis patients which improved after TKA. Conclusion. Hind foot malalignment with foot deformities (hind foot valgus) occur secondary to knee malalignment and deformities (varus deformity) in advanced osteoarthritis of knee which subsequently improve following TKA

Introduction. Radiographs and computed tomography (CT) images are used for the preoperative planning in total knee arthroplasty (TKA), however, these two-dimensional (2D) measurements are affected easily by limb position and scanning direction relative to three-dimensional (3D) bone model analyses. The purpose of our study was to compare these measurements to evaluate the factors affecting the difference. Patients and Methods. A total of 75 osteoarthritis knees before primary TKA were assessed. The full-length weight-bearing anteroposterior radiograph and CT slices were used for the 2D measurement. Three-dimensional measurement used 3D bone model reconstructed from the CT data and the coordinate system as the previous reports (Figure 1). We measured FVA (femoral valgus angle), CRA (the angle between the posterior condylar line <PC-L> and the clinical epicondylar axis <CEA>), and SRA (the angle between the PC-L and the surgical epicondylar axis <SEA>). Intra- and inter-observer reliabilities were assessed by intraclass correlation coefficients (ICC), and the differences between the 2D and the 3D measurements (Differences) were evaluated. In addition, we evaluated whether preoperative factors (preoperative extension angle, HKA, BMI and CT scanning direction) affected the differences between the 3D and the 2D measurements. Computer simulation was used to examine the influences of CT scanning direction. Results. The ICC and the mean values with 2D and 3D measurements were shown in Table 1. The mean Differences were 0.2 ± 1.2° in FVA, 0.7 ± 2.1° in CRA and 0.7 ± 1.8° in SRA. Nine percentage in CRA and 13% in SRA had over 3 degrees of the Differences. There were no significant correlations between these factors and the Difference, however, the 3D simulation showed a significant difference of CRA between the scanning direction in varus/valgus and the neutral condition (varus: p<0.001, valgus: p<0.001) (Figure 2). Discussion. From our study, the 3D measurements were highly reliable. In the 2D measurements, the rotational measurements showed less interobserver reliability because of the difficulty of picking the same CT plane and the same position of femoral bony landmarks between observers. The mean Differences were small, however, the range was large and almost10% of our cases were over 3 degrees which can induce the malalignment of the component in spite of the precise bone cutting. Particularly, smaller values of the CRA and SRA with the 2D measurement have a risk of internal-rotated position of the femoral component. Preoperative osteoarthritis knees have flexion contractures, valgus, and femoral torsion. The 3D measurements are useful to avoid the different evaluation from the CT scanning situation

INTRODUCTION. There is no effective therapy available today that alters the pathobiologic course of osteoarthritis. Recent advances have shown Mesenchymal stem cells to be a potential disease modifying treatment. Considering the tissue differentiation property and vast paracrine effects of MSCs we proposed the present study to find out the safety and efficacy of Mesenchymal stem cells in osteoarthritis of knee joint. METHODS. 12 patients with grade 1and2 bilateral osteoarthritis knee (Ahlbacks radiological grading) were selected. 8–10 ml of bone marrow was aspirated under strict aseptic precautions from the iliac spine. After the stem cell culture and expansion for 4–6 weeks the MSC suspension in 10xPBS was injected directly into the 24 knees by lateral approach. The outcome was evaluated by modified VAS score, WOMAC score, KOOS and MRI measurement of knee articular cartilage integrity by the modified WORMS score. RESULTS. Statistically significant improvement in VAS score, total WOMAC score and total KOOS score was observed from pre injection to 1st follow up at 6 weeks, 2nd follow up at 6 months and final follow up of mean 26.7 months. There was also a significant improvement from 1st follow up to 2nd and final follow up. The modified WORMS score showed a statistically significant decrease of 1.49 %. CONCLUSION. Intra-articular injection of autologous bone marrow derived culture-expanded MSCs can be considered a potential treatment of early osteoarthritis knee which relieves pain, stiffness, improves physical functions, and improves the articular cartilage integrity

To determine the effect of Dexamethasone on post-operative pain management in patients undergoing Total Knee Arthroplasty in terms of numerical pain rating scale and total opoid consumption. This Randomized Controlled Trail (RCT) was conducted for 02 years (7th September 2015 to 6th September 2017). All patients undergoing primary Unilateral Total Knee Replacement (TKR) for Osteoarthritis knee were included in the study. Patients with poor glycemic control (HbA1c > 7.6), Hepatic/Renal failure, corticosteroids/ Immunosuppression drug usage in the last 06 months, known psychiatric illnesses were excluded from the study. All patients were operated by consultant Orthopaedic surgeon under Spinal Anaesthesia and tourniquet control using medial para-patellar approach. Patients were randomly divided into 02 groups, A and B. 79 patients were placed in each group. Group A given 0.1mg/kg body weight Dexamethasone Intravenously 15 minutes prior to surgery and another dose 24 hours post-operatively while in group B (control group) no Dexamethasone given. Post-operative pain using the numerical pain rating scale (NRS) and total narcotics consumed converted to morphine dose equivalent noted immediately post-op, 12-, 24- and 48-hours post-operatively. Data analysis done using SPSS version 23. A total of 158 patients were included in the study. Of the total, 98 (62.02%) were females and 60 (37.98%) males. Average BMI of patients 26.94 ±3.14 kg/m2. Patients in group A required less post-operative analgesics (p < 0 .01) and had a better numerical pain rating scale score (p < 0 .01) as compared to group B. Pain scores at 24- and 48-hours post-op were significantly less for Dexamethasone group (p < 0 .01). Use of Dexamethasone per- and post-operatively reduces the pain and amount of analgesics used in patients undergoing TKA. For any reader queries, please contact . drjunaidrmc@gmail.com

Background. Patient satisfaction after total knee arthroplasty (TKA) has been lower than after a similar procedure, total hip arthroplasty. Poor subjective outcomes after TKA may be partially explained by abnormal kinematics patterns after TKA. The purpose of this study was to analyse rotational kinematics patterns in knees that had undergone posterior stabilized (PS)-TKA, and to clarify the relationships between rotational kinematics patterns and patient satisfaction, as well as between rotational kinematics patterns and knee function. Materials & Methods. A total of 49 osteoarthritis knees after primary PS-TKA (NexGen LPS-Flex fixed bearing knee system) were included in this study; deformed valgus, severe flexion contractures, and highly unstable knees were excluded. We used a computer navigation system and measured knee kinematics after each surgery was completed. A single investigator gently applied a manual range of motion from full extension to flexion. The angle of the internal rotation of the tibia was measured automatically at 0º, 30º, 45º, 60º, and 90º, along with maximum extension and flexion. We categorized the post-operative rotational kinematics patterns for individual cases, focusing on the initial knee flexion from 0–30º. Type A corresponded to an increased internal rotation angle of the tibia during the initial knee flexion (screw home-like movement). Type B corresponded to an increased external or an unchanged rotation angle of the tibia. We examined the range of motion (ROM) at 6 months after surgery and assessed the 2011 Knee Society Score (2011 KSS) at ≥1 year following surgery. Statistical analysis. The difference between the two groups was compared using a Wilcoxon rank sum test. Analyses were performed with JMP statistical software v8.0 (SAS Institute). A p-value of <0.05 was regarded as significant. Results. The tibia exhibited an average of 5º of internal rotation at initial knee flexion. The type A kinematics pattern achieved a better ROM and functional activity score (2011 KSS) than the type B kinematics pattern. Discussion. Modern TKA implants have been designed to reproduce normal knee kinematics to achieve better patient satisfaction and knee function. However, few reports have described the relationship between the rotational kinematics patterns at initial knee flexion and patient satisfaction. In our study, the type A postoperative rotational kinematics pattern (screw home-like movement) had better ROM and functional activity score than the type B kinematics pattern. The movement toward the internal rotation of the tibia during initial knee flexion might be important in achieving better clinical results after PS-TKA

One of four normal people had mechanical alignment of 3 degrees varus and more than so-called “constitutional varus”. Parallel joint line to the floor found in both neutral and varus alignment. Therefore, joint line orientation may play an important role in clinical outcomes after TKA. For reconstituting joint line parallel to the floor advocated by 30 varus tibial cut that was introduced by Hungerford et al. The aims of this study attempt to compare between difference radiographic parameter in term of clinical outcomes. The prospective study conducted on 94 primary varus osteoarthritis knees undergone CAS TKA using either classical method (51 knees) or anatomical method (43 knees). Clinical outcomes including WOMAC scores, Oxford knee scores and ROM were evaluated preoperatively and 6 months postoperatively. Full leg standing hip-knee-ankle were measured mechanical axis, tibial cut angle and tibial joint line angle at 6 months after surgery. The results revealed that postoperative neutral alignment (mechanical axis 0± 3°), 4–5°varus and ≥6°varus showed no significant difference in term of WOMAC scores, Oxford scores and ROM. Including comparison between classical tibial cut and anatomical tibial cut, postoperative joint line parallel to the floor and oblique joint line had no significant in clinical outcomes. Nevertheless, anatomical tibial cut and joint line parallel to the floor had significant WOMAC scores improvement than the others. In conclusion, the joint line parallel to the floor may be one of key successes after TKA more than postoperative limb alignment

Introduction. Most of the algorithm available today to balance varus knee is based on a surgeon's hands-on experience without full understanding of pathological anatomy of varus knee. The high-resolution MRI allows us to recognize the anatomical details of the posteromedial corner and the changes of the soft tissue associated with the osteoarthritis and varus deformity. We have in this study, reviewed 60 cases of severe varus knee scheduled for TKR and compared it to normal MRI and those MRI were evaluated and read by a musculoskeletal radiologist. We have documented clearly the changes that happens in soft tissue, leading to tight medial compartment. We will also show multiple short intra-operative video confirming that MRI findings. Material & method. We have retrospectively reviewed the MRI on 60 patients with advanced osteoarthritis varus knee. We also reviewed 20 MRI for a normal knee matched for age. We evaluated the posteromedial complex and MCL in sagittal PD-weighted VISTA to check the alignment of the MCL and posteromedial complex and the associate MCL bowing and deformity that could happen in osteoarthritis knee. We have measured the thickness of the posteromedial complex and the posterior medial bowing of the superficial MCL and the involvement of the posterior oblique ligament in those patients. To measure the posterior bowing of the MCL, a line was drawn through the posterior aspect of both menisci and we measured the distance between the posterior edge of MCL to that line in actual image. To measure the thickness of the posteromedial complex, we measured it at two areas in the posterior medial corner posteriorly at the level of the medial meniscus. Measuring the medial bowing of the MCL was done by a line drawn through the medial edge of the femoral condyle and the tibial condyle at the level of the medial meniscus to the inner aspect of the MCL. The normal distance between the posterior aspects of the MCL to the posterior meniscus line was approximately measured 2 cm. in average. Results. We were able to recognize and measure the medial deviation of MCL in all arthritic knees due to the deformity and the effect of the medial margin osteophyte and medial extrusion of the meniscus. Thickening of posteromedial complex was recognized in the majority of the cases with prominent thickening seen in 50/60 knees with average thickness measuring approximately 1.2 cm due to the synovial thickening, adhesions, granulation tissue, degenerated medial meniscus, and involvement of the posterior oblique ligament and the capsular branch of the semimembranosus tendon, as well as the oblique popliteal ligament. The involvement of posterior oblique ligament were seen in majority of the cases. In 55 cases we have showed a heterogeneous appearance of the ligament and loss of normal signal within the postero medial complex and we have documented that the oblique ligament will cause the posterior bowing of the MCL. The medial bowing of the MCL is also correlated to the severity of the varus deformity with an average distance to the normal medial line of the medial meniscus measuring approximately 1.1 cm. Discussion. Our study shows that the changes affecting the superficial MCL is likely to be secondary to the obvious changes involving the posteromedial complex and to the marginal osteophyte as well as the extrusion of the medial meniscus. Also, we have confirmed that there are deforming structures such as the oblique ligament with adhesion and thickening with all the posterior medial complex. Those changes clearly caused the posterior bowing to the superficial MCL without an actual shortening of the ligament. The scarring tissue in the posteromedial corner and the adhesion is acting as a soft phyte tensioning and deforming the ligament and the posterior capsule. The oblique ligament act as a deforming forces forcing the superficial MCL to bow posteriorly. The lengths of the superficial MCL stayed the same. Conclusion. The conventional wisdom of releasing the distal attachment of the superficial medial MCL to balance knee has to be a challenge based on our MRI finding. Releasing the superficial MCL can sometimes lead to a major instability of the knee requiring a more constrained implant. Our MRI assessment clearly showed that the Superficial MCL is deformed because of posterior bowing and medial bowing and considerable thickening of the posteromedial corner, as well as the accompanying osteophyte. We believe that clearing the superficial MCL and excising those thickened scar tissue in the posterior medial corner will enable us to balance the knee without creating instability Conclusion: The conventional wisdom of releasing the distal attachment of the superficial medial MCL to balance knee has to be a challenge based on our MRI finding. Releasing the superficial MCL can sometimes lead to a major instability of the knee requiring a more constrained implant. Our MRI assessment clearly showed that the Superficial MCL is deformed because of posterior bowing and medial bowing and considerable thickening of the posteromedial corner, as well as the accompanying osteophyte. We believe that clearing the superficial MCL and excising those thickened scar tissue in the posterior medial corner will enable us to balance the knee without creating instability

Introduction. Several methods, based on both functional and anatomical references, have been studied to reach the goal of a proper knee kinematics in total knee arthroplasty (TKA). However, at present, there is still a large debate about which is the most precise and accurate method to achieve the correct rotational implant positioning. One of the main methods already used in TKA to describe the tibiofemoral flexion-extension movement, based on a kinematic technique, thus not influenced by the typical variability related to the identification of anatomical references, is called “functional flexion axis” (FFA) method. The purpose of this study was to determine the repeatability in estimating knee functional flexion axis, thus evaluating the robustness of the method for navigated total knee arthroplasty. Methods. Passive kinematic and anatomical acquisitions were performed with a commercial navigation system on 87 patients undergoing TKA with primary osteoarthritis. Knee FFA was estimated, before and after implant positioning, from three flexion-extension movements between 0° and 120° (Figure 1). The angle between Functional Flexion Axis and an arbitrary clinical reference, the transepicondylar axis (TEA), was analysed in frontal and axial view (Figure 2). Repeatability Coefficient and Intraclass Correlation Coefficient (ICC) were estimated to analyse the reliability and the agreement in identifying the axis. Results. The analysed angle between FFA and TEA presented differences between pre- and post-operative conditions only in the frontal plane (from −8.3° ± 5.5° to −2.8° ± 5.3°) (p < 0.0001). There was good intra-observer reliability and agreement. Repeatability coefficient ranged between 4.4° (3.7° – 4.9°) and 3.4° (2.9° – 3.8°), the ICC between 0.87 (0.83 – 0.91) and 0.93 (0.90 – 0.95) and the standard deviation ranged between 1.3° and 1.0°. Conclusions. The present study demonstrated that total knee arthroplasty affected the estimation of FFA only in the frontal plane. The FFA method has good repeatability both in pre- and post-operative conditions, thus it can be considered for clinical purposes, including navigated knee arthroplasty, as well. Since the FFA is surgeon-independent and avoids the bias due to anatomical landmarks identification, this could potentially provide an alternative technique to plan implant positioning in total knee arthroplasty

The alignment of the knee following total knee arthroplasty (TKA), especially tibial alignment, is a major factor determining the long-term survival of the prosthesis. A disadvantage of using extramedullary alignment guides of the tibia for TKA is the difficulty in correctly identifying the ankle center, and surgeons cannot construct the tibial mechanical axis correctly without the correct location of the ankle center. Although numerous studies have reported bony and soft tissue landmarks for determining the ankle center, a consensus has yet to be reached regarding this matter. This problem is complicated by rotational mismatch between the knee and ankle joint. Because it is difficult to frontalize the knee and ankle joints simultaneously on the same frontal plane. When using extramedullary alignment guides of the tibia, the guides should be applied to the tibia while keeping the knees frontal. The purpose of this study was to determine the position of the ankle center, which is useful for setting extramedullary alignment guides, by using CT data of osteoarthritic knees. CT data of fifty patients (fifty knees) with varus osteoarthritic knees for primary TKA were retrospectively analyzed. Tibial anteroposterior (AP) axis and transmalleolar axis (TMA) were used as reference axes of the knee and ankle joint, respectively. When using above these reference axes, the offset distance from the bimalleolar center was measured as the position of the ankle center. The angular errors were defined as the varus angle of the proximal tibial cut caused by this offset distance when the position of the ankle center was regarded as the bimalleolar center. The position of the ankle center was 1.5 ± 1.2 mm and 2.3 ± 1.5 mm medial to the bimalleolar center with reference to tibial AP axis and TMA, respectively. There was a significant difference between the position of the ankle center with respect to the tibial AP axis and with respect to the TMA (p < 0.01). The mean angular error with respect to the tibial AP axis was 0.3 ± 0.2 °, and the value with respect to TMA was 0.4 ± 0.2 °. The maximum varus angular error along tibial AP axis was less than 0.7 degrees. The positions of the ankle center differed according to the reference axis. Since the angular error was small enough, the bimalleolar center along the tibial AP axis could be used as the ankle center in TKA patients with osteoarthritis knees

An ACL reconstruction is designed to restore the normal knee function and prevent the onset and progression of degenerative changes such as osteoarthritis. However, contemporary literature provides limited consensus on whether knee degeneration can be attenuated by the reconstruction procedure. The aim of this pilot study was to identify the presence of early osteoarthritis after ACL reconstruction using MRI analysis. 19 patients who had undergone an ACL reconstruction (9 isolated ACL rupture, 8 ACL rupture and meniscectomy, 2 ACL rupture and meniscal repair) volunteered for this study. MRI's were collected preoperatively and postoperatively for analysis with a mean follow up of 23 months. The Boston-Leeds Osteoarthritis Knee Score (BLOKS) was used for the analysis of the articular cartilage by a consultant orthopaedic surgeon. Scores ranged from 0–3, with 0 being total coverage and thickness of the cartilage and 3 being no coverage. Qualitative analysis was then conducted on each patient to determine if the articular cartilage improved, degenerated, or did not change between preoperative and follow-up scans. All patients with isolated ACL rupture were found to either have no change or improved articular cartilage scores in their follow up scans compared preoperatively. In contrast, patients with a meniscal repair displayed worse cartilage scores postoperatively. Lastly, of the patients who had an associated meniscectomy, 6 had worse follow-up results, with the remaining patients showing no change or improved cartilage scores. The present results indicate that patients with an isolated ACL rupture have a reduced risk of developing OA compared to those with associated meniscal injuries. This has implications for analysing the outcome of current ACL reconstruction techniques and in predicting the likelihood of patients developing OA after ACL reconstruction. Future work will involve confirming this pattern in a larger patient sample, as well as exploring additional factors such as time to surgery delay and rehabilitation strategy

Gap planning in total knee arthroplasty (TKA) navigation is critically concerned. Osteophyte is one of the contributing factors for gap balancing in TKA. The osteophyte is normally removed before gap planning step. However, the posterior condylar osteophyte of femur is sometimes removed during the flexion gap preparation or may not be removed at all depends on individual case. This study attempts to investigate on how posterior condylar osteophyte affects on gap balancing and limb alignment during operation. The study was conducted on 35 varus osteoarthritis knees with posterior condylar osteophyte and undergone on TKA navigation. All knees were measured by CT scan for the size of posterior condylar osteophyte according to its width. Extension gap, flexion gap width, and limb alignment were measured by using the tension device with distraction force of 98 N on both medial and lateral sides under computer assisted surgery. The measuring of extension gap, flexion gap width, and limb alignment was undertaken before and after the posterior condylar osteophyte removal. This study reveals that the mean of the size of posterior condylar osteophyte after removal is 8.96 mm. The posterior condylar osteophyte has an effect on the increasing of medial extension gap and lateral extension in average 0.74 ± 0.72 mm. and 0.42 ± 0.67 mm. respectively. It also increases 0.71 ± 1.00 mm. in medial flexion gap and 0.97 ± 1.47 mm. in lateral flexion gap. After the posterior condylar osteophyte removal the mean of varus deformity is decreased 0.90° ± 1.14 ° while the mean of extension angle of sagittal limb alignment is increased 1.61°±1.69°. There is also a significant relationship between the size of posterior condylar osteophyte and the increasing of lateral flexion gap and also with the varus deformity decreasing. If the size of posterior condylar osteophyte is increased 10 mm. the lateral flexion gap will be increased 1.15 mm. and varus deformity will be decreased 0.75 degree

Introduction. MERA Quest Knee System (Quest Knee) is a posterior cruciate ligament–retaining prosthesis considering the anatomical features and lifestyles of the Japanese. As for the anatomical features, we reduced the size of prosthesis and set a smaller interval of sizes because Japanese knees are smaller and flatter than those of Caucasians. As for the lifestyles, we evaluated in vivo patellar tracking during deep knee flexion and the condylar geometry in the axial plane of magnetic resonance imaging. It was found that the patella sank deeply into the intercondylar notch and that the articular surface of the lateral condyle began to curve steeply. We adopted this shape and engraved the lateral condyle deep to reduce the pressure of the patellofemoral joint and to get better range of motion (ROM). For the contact pressure rise in the femorotibial joint by engraving the lateral condyle, the insert was suited to the shape of the femoral component. Furthermore, we increased the thickness of the posterior flange of the femoral component and changed the posterior radius of curvature gradually, and this shape allowed the flexion of 155°. We have used Quest Knee for clinical applications from October 2009. We studied the short-term results of Quest Knee. Methods. Between June 2010 and July 2013, the same senior surgeon performed 59 consecutive primary operations with Quest Knee. Forty patients (44 knees) were women, and 14 patients (15 knees) were men. The mean patient age was 72.5 years (range, 59–89 years). All were osteoarthritis knees. Coronal deformity was varus in 58 knees and valgus in one knee. All operations were performed with a measured resection technique, and all patellae were resurfaced. Clinical evaluations were assessed using the Japanese Orthopaedic Association knee rating score (JOA score), and clinical ROM and standing femorotibial angle (FTA) were measured. Additionally, three-dimensional motion analysis of the patellar component during squatting was performed by the image matching method with image correlations. Results. The mean follow-up period was 17.4 months (range, 6–43 months). The JOA score at preoperative and follow-up were 57.5 ± 10.1 and 87.5 ± 5.6 points, respectively (P < 0.0001) (Fig. 1). The ROM at preoperative and follow-up were 127.4 ± 11.1 and 126.2 ± 9.0° (P = 0.47) (Fig. 2). The mean FTA at preoperative and follow-up were 184.2 and 172.3°. With regard to the three-dimensional motion analysis, the patella showed lateral shift during squatting (Fig. 3). Discussion. As for the patellofemoral contact pressure at flexion in total knee arthroplasty, a biomechanical study has reported that the pressures of posterior cruciate ligament–retaining and posterior-stabilized knees were 3.2 and 2.8 times as much as the body weight. This report suggests that the reduction of the pressure of the patellofemoral joint during deep knee flexion results in better ROM. We suppose that Quest Knee reduced the pressure, led the patella to the lateral side, and achieved better ROM. Conclusions. Short-term results of Quest Knee were good. More detailed studies are needed to get better function and long-term durability

Introduction. To achieve well aligned and balanced knee is essential for the post-operative outcome in total knee arthroplasty (TKA). Gap balancing technique can adjust the bone cut depending on the soft tissue balance in addition to soft tissue releases. Therefore, gap balancing technique would be more advantageous in soft tissue balance comparing to measured resection technique (MRT) in which soft tissue balancing relayed on soft tissue releases alone. Nevertheless, the influence of surgical technique on the post-operative knee stability has not been fully investigated. Objective. We introduced a new surgical technique (medial gap technique: MGT) according to modified gap technique regarding medial knee stability as important. The intra-operative soft tissue balance and post-operative knee stability were compared between MGT and MRT in posterior-stabilized (PS) TKA for varus type osteoarthritic knees. Materials & Methods. Sixty varus type osteoarthritis knees were involved in this study. PS type TKAs (NexGen LPS flexR) were performed using MGT in 30 knees (MGT group) and MRT in 30 knees (MRT group). The extension gap was made in the same manners in both groups. Both femoral and tibial bone cuts were perpendicular to the mechanical axis. Medial soft tissue releases were limited until the spacer block with the thickness corresponding to the resected lateral tibial condyle could be inserted. After extension gap was prepared, OFR-tensorR was used to assess soft tissue balance (center gap, varus angle) at extension and flexion prior to posterior femoral condyle bone resection. Both differences of the center gap and varus angle between at extension and flexion were calculated and used for size selection and external rotation angle of femoral component in MGT. The final joint component gaps were evaluated using OFR-tensorR with both femoral trial in place and patello-femoral joint reduced at 0, 10, 30, 45, 60, 90, 120 and 135 degrees of flexion. Quantitative stress radiographies were performed at 1 month, 6 months and 1 year post-operatively to assess joint stability. Joint opening distance (mm) at both medial and lateral joint compartment were measured with knee extension and flexion. Each parameter was compared between MGT and MRT group using unpaired t-test (p<0.05). Results. Pre-operative factors showed no significant differences between 2 groups. The joint component gaps were significantly larger in MRT group from 45 to 135 degrees of flexion (Fig.1). The joint opening at the lateral compartment was significantly larger than medial at both knee extension and flexion in both groups. The joint openings were significantly larger bilaterally in MRT group comparing to MGT group at both extension and flexion (Fig.2, 3). Discussions. Medial instability has been reported as a possible reason for the persistent knee pain after TKA in the varus knees. We proposed a new surgical technique (MGT) not to deteriorate medial stability and allow lateral looseness in TKA. Post-operative knee stability was superior in MGT group comparing to MRT group from one month to one year after surgery. The difference of the intra-operative soft tissue balance might play an important role on the post-operative knee stability

Background. Polymethylmethacrylate (PMMA) has been used for total knee arthroplasty (TKA) as a method of fixation; however, its durability has been questionable for the long-term use because of the loosening after the cement deterioration, its vulnerability toward infectious resistance, and a smaller amount of healthy bone left for the knee revision surgery. Especially, a decrease of bone density on the proximal tibia has been believed to be triggered as a result of stress shielding. When compared with a cemented TKA, a cementless TKA reduces the amount of bone loss after surgery. In 1999, the Trabecular Metal (TM), with its main composition being the porous tantalum metal, became available as a choice of the porous cementless knee joint prosthesis. The characteristics of porous tantalum metal are its great affinity to the bone as well as its similarity to cancellous bone. The porous tantalum metal starts to bond with osteoblasts, and fills up 80% of porous structure in one year; therefore, it has been characterized by its higher initial fixation strength. However, it is questionable if strong fixation strength due to bone ingrowth between the tibial tray mainly made up with the porous tantalum metal and a cancellous bone will continually be kept. Bobyn, JD, Dunbar et al. have acknowledged the existence of bone ingrowth based on the radiographic evaluation; however, their data had not been quantified in their report. In this study, the bone ingrowth density have periodically quantified using 3D bone morphometric software (TRI/3D-BON64.RATOC) after taking CT of the knee joint prosthesis. Material and Methods. From October 2011, we have reviewed 45 medial osteoarthritis knees that underwent MIS-TKA using Trabecular Metal Modular Tibia CR-type (Zimmer, Inc, Warsaw, Indiana). Ages range from 61–89 years (mean, 74.5 years), and 5 males (7 knees), and 32 females (38 knees) participated in this study. After taking CT picture with the Phantom under lower extremities, the bone ingrowth density are quantified utilizing 3D bone morphometric software (TRI/3D-BON63.RATOX). Measured areas are divided into 6 zones that are right under the pegs of TM femoral component, and the bone ingrowth density (BMC/TC) between TM and cancellous bone were periodically measured on 3, 6, 9, 12,15,18,21,24.27 months after the surgery. Also, intra-zone comparison were implemented by each period among Medial (Zone 1), Lateral (Zone 2), Medial Anterior (Zone 3), Medial Posterior (Zone 4), Lateral Anterior (Zone 5), and Lateral Posterior (Zone 6). Mann-Whitney U test and Student's t-test were used for statistical analysis. All cases of tibial component alignment was within 3 degree varus-valgus to neutral alignment. Results. Bone ingrowth and formation was increased to nine months from six months after surgery and was reduced to 12 months postoperatively. But bone resorption was aboloished 18 months after surgery without influence stress shieldings. In detail, the result was significant higher bone ingrowth and formation in medial than lateral region. I recognized that lateral lesion was affected by stress shieldings. The results was not significant difference of bone ingrowth between medial anterior and posterior region but significant difference of bone ingrowth in lateral posterior than lateral anterior

Introduction. The purpose of this study is to evaluate the mid-term results of clinical and radiographic results Hi-tech knee a cementless total knee arthroplasty (Nakashima medical Co. Ltd., Okayama, Japan). This TKA system was developed in Chiba University from 1994. The characteristic of this system are flat on flat CR-TKA and cementless fixation. Contact surface are made of titanium alloy and UHMWPE, which is produced by the direct compression mold manufacturing method. Material and Method. Between May 1998 and May 2005, we performed 53 consecutive primary TKAs for 42 patients. There were 41 women and 1 man with a mean age of 64.4 years (39 to 78 years). The average follow up period was 7 years 8 months (5 years to 12 years). Osteoarthritis knee were 21 knees and rheumatoid arthritis were 32 knees. The mean pre-operative FTA was 181.7 degrees (168 to 203 degrees). The method of the operation went in measured cut technique for all cases. All 53 knees were implanted with a cruciate retaining prosthesis. All comportments, included a patella component, were fixed without cement. Clinical evaluations were performed according to American Knee Society (KS) system, knee score and function score. Results. The mean preoperative and postoperative, at the latest follow up, maximum flexion angles were 104 and 114 degrees, respectively. The KS knee score and function score improved from 47.5 and 38.9 points before surgery to 87.6 and 80.4 points after surgery, respectively. Postoperative alignment FTA average 174.8 degrees. Within follow up period, it maintained good valgus-varus stability. There was no major loosening. Six knees (11%) were observed radiolucent line at medial tibia plateau less than 1mm. No revisions of TKA were required because of loosening or sinking. There was also no problem at patellar component. Conclusions. Hi-Tech knee a cementless TKA system was made for the suitable for a Japanese knee, strong initial fixation in a concept. The patella component is also cementless fixation. Contact surface are made of titanium alloy and UHMWPE of the direct compression mold method, it was able to protect the abrasion of the polyethylene in a stable state, too. The mid-term results of Hi-Tech knee a cementless TKA, not only OA but also RA patient knee, provided almost good results

A 51 years old female who experienced difficulty in gait ambulation due to secondary osteoarthritis of knee showed knee instability caused by paralysis associated with poliomyelitis and scoliosis. At the first medical examination, right knee range of motion was 0° to 90°, and spino malleolar distance (SMD) showed 72cm for the right leg, 78cm for the left leg, and the bilateral comparison of SMD indicated the leg length discrepancy of 6cm. The patient has a history of surgeries with an anterior – posterior instrument for the treatment of scoliosis, and with Langenskiöld method for the paralyzed right knee at the age of seventeen. The patient also experienced varus degeneration at the age of twenty seven, which was surgically treated with high tibial osteotomy. In this case, a reoperation of her right knee was performed due to the reoccurrence of the knee pain. Preoperative planning was performed using Patient-matched instrument (Signature; Biomet) which was created based on computed tomography data. Each part of osteotomy followed the resection guide by Signature, and a total knee arthroplasty was carried out using the Rotating Hinge Knee System (Zimmer, warsaw. Inc). Two week after the operation, the patient showed the ability to walk without any assistance, and has been in a good condition

Purpose. The purpose of this study is to investigate the relationship between the angles made by the reference axes on the computerized tomography (CT) images and comparison of the knee alignment between healthy young adults and patients who is scheduled to have total knee arthroplasty. Materials and Methods. This study was conducted in 102 patients with osteoarthritis of knee joint who underwent preoperative computerized tomography (CT). The control group included 50 patients having no arthritis who underwent CT of knee. Axial CT image of the distal femur were used to measure the angles among the the anteroposterior (AP) axis, the posterior condylar axis (PCA), clinical transepicondylar axis (cTEA) and the surgical transepicondylar axis (sTEA). Then, the differences in amounts of rotation between normal and osteoarthritic knee was evaluated. Results. The mean angle between cTEA and PCA in the osteoarthritis group was 5.0°±2.2, whereas that in the control group was 5.5°±2.0. The mean angle between cTEA and sTEA in the osteoarthritis group was 3.7°±0.8, whereas that in the control group was 4.3°±0.6. The mean angle between AP axis and PCA in the osteoarthritic group was 93.25°±2.0, whereas in the control group was 96.3°±1.9. There was significant differences in angles between AP axis and PCA. But, no significant difference was seen in angles between cTEA and PCA, cTEA and sTEA in two groups. Conclusion. In result of this study, the angle between cTEA and PCA showed an average external rotation of 5.0° in osteoarthritic group. More external rotation was needed for the femoral component alignment than 3° recommended in usual total knee arthroplasty. The angle between AP axis and PCA is decreased in osteoarthritic knee compared with normal knee. But, osteoarthritic change of knee joint had no significant effect on the relationships of other axes

Introduction. Using the tibial extramedullary guide needs meticulous attention to accurately align the tray in total knee arthroplasty (TKA). We previously reported the risk for varus tray alignment if the anteroposterior (AP) axis of the ankle was used for the rotational direction of the guide. The purpose of our study was to determine whether aligning the rotational direction of the guide to the AP axis of the proximal tibia reduced the incidence of varus tray alignment when compared to aligning the rotational direction of the guide to the AP axis of the ankle. Materials and Methods. Clinical Study. A total of 80 osteoarthritis (OA) knees after posterior stabilized TKA were recruited in this study. From 2002 to 2004, the rotational alignment of the guide was adjusted to the AP axis of the ankle (Method A: Figure 1, N = 40 knees). After 2005, the rotational alignment of the guide was adjusted to the AP axis of the proximal tibia (Method B: Figure 1, N = 40 knees). The AP axis of the proximal tibia was defined as the line connecting the middle of the attachment of the PCL and the medial third border of the attachment of the patellar tendon. The guide was set at a level of 10 mm distal to the lateral articular surface. Postoperative alignment was compared between the two groups using full-lengthanteroposterior radiograph. Computer simulation. Computer simulation was performed to determine the effect of ankle rotation on tibial tray alignment, using three-dimensional bone and skin model reconstructed from CT images of 75 OA knees (Figure 2). The position of the distal end of the guide in Method B was evaluated on the coronal plane perpendicular to the AP axis of the proximal tibia and of the ankle respectively. <Displacement> was the distance from the distal end of the guide to the midpoint-malleolar points (+: medial position). <Distance ratio> was the ratio of <Displacement> dividing by the entire width of the malleolar. Results. The results of the postoperative alignment for both methods from the clinical study are shown in Table 1. The number of the knees with more than 3 degrees of varus aligned tibial component significantly decreased with the Method B from the Method A. The computer simulation showed that the position of the guide varied great among individuals in the direction of the AP axis of the ankle joint. Discussion. When an extramedullary alignment guide is used in TKA, a rotational mismatch between the proximal part of the tibia and the ankle joint can induce a varus alignment of the tibial component. Computer simulation also supported our conclusion that the surgeon should not evaluate the distal end of the guide in the direction of the ankle joint to minimize the effects of anatomic variation for proper coronal alignment